For example, in a fin-type channel field effect transistor (fin-FET) which is a three-dimensional device, a fin-type channel having a plurality of Si fins is formed on the bottom of a fine trench formed in an insulating film (SiO2 film and SiN film), and a Ti film, for example, is formed as a contact metal on the source and drain portions thereof. Thus, a contact is formed. The source and drain portions of the fin-type channel are formed by epitaxially growing Si or SiGe on the Si fins. From the viewpoint of improving the contact performance, a step of removing a natural oxide film (SiO2 film) formed on the surface of the source and drain portions is performed before forming the contact metal.
As a technique for removing the natural oxide film of the source and drain of the fin-FET, there has been known anisotropic etching by ionic etching.
Further, since the structure of the source and drain portions of the fin-FET is complicated, a chemical oxide removal (COR) processing is considered as a processing capable of removing the natural oxide film in a portion where ions hardly reach. The COR processing is a processing of removing an oxide film by plasmaless dry etching using HF gas and NH3 gas, and is described in, for example, International Publication No. 2007/049510.